
/*
 * Copyright 2002-2022 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 *版权所有2002-2022原作者。
 *
 *根据Apache许可证2.0版许可（“许可证”）；
 *除非符合许可证的规定，否则您不得使用此文件。
 *您可以在以下网址获取许可证副本：
 *
 *https://www.apache.org/licenses/LICENSE-2.0
 *
 *除非适用法律要求或书面同意，软件
 *根据许可证进行的分发是在“按原样”的基础上进行的，
 *无任何明示或暗示的保证或条件。
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 */

package org.springframework.scheduling;

import java.time.Instant;
import java.util.Date;

import org.springframework.lang.Nullable;

/**
 * Common interface for trigger objects that determine the next execution time
 * of a task that they get associated with.
 *
 * @author Juergen Hoeller
 * @since 3.0
 * @see TaskScheduler#schedule(Runnable, Trigger)
 * @see org.springframework.scheduling.support.CronTrigger
 */
/**
 *用于确定下一次执行时间的触发器对象的通用接口
 *与他们相关联的任务。
 *
 *@作者于尔根·霍勒
 *@自3.0起
 *@请参阅TaskScheduler#计划（可运行，触发器）
 *@参见org.springframework.scheduling.support.CronTrigger
 */
public interface Trigger {

	/**
	 * Determine the next execution time according to the given trigger context.
	 * <p>The default implementation delegates to {@link #nextExecution(TriggerContext)}.
	 * @param triggerContext context object encapsulating last execution times
	 * and last completion time
	 * @return the next execution time as defined by the trigger,
	 * or {@code null} if the trigger won't fire anymore
	 * @deprecated as of 6.0, in favor of {@link #nextExecution(TriggerContext)}
	 */
	/**
	 *根据给定的触发器上下文确定下一个执行时间。
	 *<p>默认实现委托给{@link#nextExecution（TriggerContext）}。
	 *@param triggerContext上下文对象封装上次执行时间
	 *以及最后完成时间
	 *@返回触发器定义的下一个执行时间，
	 *或者{@code-null}，如果触发器不再触发
	 *@从6.0起已弃用，支持{@link#nextExecution（TriggerContext）}
	 */
	@Deprecated(since = "6.0")
	@Nullable
	default Date nextExecutionTime(TriggerContext triggerContext) {
		Instant instant = nextExecution(triggerContext);
		return instant != null ? Date.from(instant) : null;
	}

	/**
	 * Determine the next execution time according to the given trigger context.
	 * @param triggerContext context object encapsulating last execution times
	 * and last completion time
	 * @return the next execution time as defined by the trigger,
	 * or {@code null} if the trigger won't fire anymore
	 * @since 6.0
	 */
	/**
	 *根据给定的触发器上下文确定下一个执行时间。
	 *@param triggerContext上下文对象封装上次执行时间
	 *以及最后完成时间
	 *@返回触发器定义的下一个执行时间，
	 *或者{@code-null}，如果触发器不再触发
	 *@自6.0起
	 */
	@Nullable
	Instant nextExecution(TriggerContext triggerContext);

}
